Ziegler-natta catalysts for olefin polymerization

ABSTRACT

The present invention relates to use of optionally monosubstituted 2,2-di(tetrahydrofuryl)methanes, as internal donors in Ziegler-Natta catalysts to obtain polymers with desirable properties. The present disclosure further concerns Ziegler-Natta catalyst components comprising said optionally monosubstituted 2,2-di(tetrahydrofuryl)methanes and Ziegler-Natta catalysts for olefin polymerization comprising said Ziegler-Natta catalyst components as well as a method for preparing the same and their use in providing polyolefins.

FIELD OF THE DISCLOSURE

The present invention relates to optionally monosubstituted 2,2-di(tetrahydrofuryl)methanes, and more particularly to their use as internal donors in Ziegler-Natta catalysts to obtain polymers with desirable properties, in particular regarding molecular weight distribution (MWD) and chemical composition distribution (CCD). The present disclosure further concerns Ziegler-Natta catalyst components comprising said optionally monosubstituted 2,2-di(tetrahydrofuryl)methanes and Ziegler-Natta catalysts for olefin polymerization comprising said Ziegler-Natta catalyst components, as well as a method for preparing the same and their use in providing polyolefins.

BACKGROUND OF THE DISCLOSURE

Ziegler-Natta (ZN) type polyolefin catalysts are well known in the field of producing polyolefins, such as ethylene (co)polymers. Generally, the catalysts comprise at least a catalyst component formed from a transition metal compound of Group 4 to 6 of the Periodic Table (IUPAC, Nomenclature of Inorganic Chemistry, 2005), a metal compound of Group 1 to 3 of the Periodic Table (IUPAC), optionally a compound of Group 13 element of the Periodic Table (IUPAC), and optionally an internal electron donor. A ZN catalyst may also comprise further catalyst component(s), such as a cocatalyst and optionally an external electron donor.

Internal electron donor and internal donor have the same meaning and are interchangeable in this application. The same applies to an external electron donor and an external donor, respectively.

The catalyst composition used for the production of polyolefins, such as ethylene (co)polymers, determines i.a. the properties of the polymers. Thus, the catalyst composition allows for “tailoring” the properties of the produced polymers.

EP373999 A1 discloses a method for controlling the molecular weight distribution (MWD) of polyethylene homopolymers and copolymers using a Ziegler-Natta catalyst comprising an external electron donor selected from monoethers (e.g. tetrahydrofuran). It is suggested to add the monoether to the catalytic component in the presence of the cocatalyst, whereas it is strongly discouraged to contact the monother and the catalytic component in the absence of the cocatalyst.

WO2007051607 A1 discloses another possibility of tailoring the properties of a multimodal ethylene polymer. An alkyl ether type internal electron donor, preferably tetrahydrofuran, is used to modify the Ziegler-Natta catalyst component and to influence the molecular weight distribution (MWD) of a higher molecular weight (HMW) component.

WO2004055065 A1 discloses a solid catalyst component which comprises Ti, Mg, halogen, and an electron donor in specific molar ratios for the preparation of copolymers of ethylene with a-olefins, where said a-olefins are homogeneously distributed along the polymer chains. The electron donor (ED) is preferably ether, such as tetrahydrofuran. Said catalyst component is used in polymerization processes together with an alkyl aluminium compound and optionally with external electron donor. The optional external electron donor is said to be equal to or different from the ED used in catalyst component.

WO2007147715 A1 discloses a catalyst component for the polymerization of olefins, which is obtained by a specific process, comprising Mg, Ti, halogen and 1,3-diethers as internal electron donors. The catalyst with 9,9-bis(methoxymethyl)fluorene as an internal electron donor is used for propylene polymerization.

EP0376936 A2 discloses a MgCl₂-supported Ziegler-Natta catalyst, where spray-dried MgCl₂/alcohol carrier material is treated with a compound of group IA to IIIA (Groups 1, 2 and 13 of the Periodic Table according to IUPAC, Nomenclature of Inorganic Chemistry, 2005) then titanated with a titanium compound, optionally in the presence of internal electron donor. The optional internal donor compound (THF or di-isobutyl phthalate are given in those examples where internal electron was used) is added together with TiCl₄ or after addition TiCl₄. However, the activity of the donor-modified catalysts of EP0376936 A2 was much lower than the original catalyst without the donor. Moreover, during the donor treatment step, a 10 wt % solution of triethylaluminium and a number of catalyst hydrocarbon washes were used, which resulted in a large amount of organic solvent waste.

WO2014004396 A1 discloses a catalyst component, where bi-heterocyclic compounds are used as internal electron donor. The catalyst component is used for propylene polymerization.

WO2014096296 A1 discloses a supported Ziegler-Natta catalyst component comprising an internal donor selected from bi-(oxygen containing ring) compounds and use of such a catalyst component for preparing a catalyst system used in the polymerization of ethylene for producing high molecular weight polyethylene.

WO2013098139 A1 discloses a particulate Group 2 metal/transition metal olefin polymerization catalyst component, which is obtained by a specific process, comprising 1,3-diether compound as internal donor and the use of such a catalyst component for preparing a catalyst used in the polymerization of olefins, particularly propylene polymerization.

WO2016097193 A1 discloses a solid MgCl₂-based Ziegler-Natta catalyst component, prepared by pre-treating a MgCl₂*mROH adduct with a compound of Group 13 element and an internal organic compound being a bicyclic ether, and further treated with a compound of Group 4 to 6 transition metal for producing polyolefins. Further disclosed is a preparation of said catalyst component, as well as a Ziegler-Natta catalyst comprising said solid catalyst component, a compound of Group 13 element as cocatalyst and optionally external additives.

Although much development work in Ziegler-Natta catalyst preparation has been accomplished, there is still room for further improvement. Further, nowadays health, safety and environment policies are an important factor in the production of catalysts and further polymers. In other words, polymers must fulfill the strict health and environmental requirements of certain national and international institutions. One class of substances considered as potential harmful compounds is phthalates, which have been commonly used as internal electron donors in Ziegler-Natta type catalysts. In addition, tetrahydrofuran has been classified as a hazardous substance.

For these reasons, it is still desirable to find further internal donors for use in Ziegler-Natta catalysts which do not include phthalates and/or tetrahydrofuran and which provide desired polymer properties, e.g. high molecular weight. Further, from a commercial point of view, such catalysts should exhibit a reproducible morphology, composition and performance.

There is also a need to find a catalyst which is able to produce copolymers with wider melt flow rate (MFR) and density windows, such that there is the possibility to produce high molecular weight copolymers with narrow MWD (molecular weight distribution) and high comonomer content combined with low melting temperature.

Finally, the catalyst should demonstrate productivity on a level that makes it viable in commercial polymerization processes while producing polymers with a broad range of molecular weight.

Based on the teachings of prior art, it appears that donor modification might result in the improvement of some properties. However, very often these improvements are made at the expense of catalyst activity and comonomer response. In particular, MgCl₂-based catalysts prepared by precipitation methods are typically sensitive towards changes in preparation conditions.

BRIEF DESCRIPTION OF THE DISCLOSURE

An object of the present invention is to provide internal donors, and in particular, a Ziegler-Natta catalyst component comprising said internal donor, which overcomes the above disadvantages, is environmentally sustainable and supports the preparation of ethylene (co)polymers with a desirable molecular weight distribution (MWD) and chemical composition distribution (CCD).

The object of the present invention is achieved by use of compounds of formula (I) as internal donors, a Ziegler-Natta catalyst component comprising said internal donors, a Ziegler-Natta catalyst comprising the same, and use thereof in olefin polymerization, which are characterized by what is stated in the independent claims. The preferred embodiments of the present invention are covered by the dependent claims.

DETAILED DESCRIPTION OF THE DISCLOSURE

Surprisingly it has now been found that the use of compounds of formula (I) as discussed herein and hereafter in Ziegler Natta catalyst system provides excellent activity—hydrogen response balance when utilized in (co)polymerization of ethylene. Additionally, their use provides ethylene (co)polymers with desired molecular weight, molecular weight distribution (MWD) and chemical composition distribution (CCD).

Internal Donor (i)

Accordingly provided herein is the use of a compound of formula (I) as an internal donor in a Ziegler-Natta catalyst, especially for ethylene (co)polymerization, in particular for producing ethylene (co)polymer in a multi-stage process,

wherein

R₁ is selected from a group consisting of H, a linear or branched C₁₋₇-alkyl, CH₂OR₂, and an oxygen-containing heterocyclic ring; and

R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.

Preferably, R₁ is selected from a group consisting of H, linear or branched C₁₋₅-alkyl, and tetrahydrofuryl. More preferably, R₁ is selected from a group consisting of H, C₁₋₃-alkyl and 2-tetrahydrofuryl, and most preferably R₁ is selected from a group consisting of H, methyl and 2-tetrahydrofuryl.

Preferred embodiments of the use of the present internal donor are described in the dependent claims as well as in the following description.

In a first preferred embodiment of the invention, the compound of formula (I) is selected from compounds of formula (I-a)

wherein

R_(1a) is selected from a group consisting of H, a linear or branched C₁₋₇-alkyl and CH₂OR₂; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.

Preferably, R_(1a) is selected from a group consisting of H and methyl.

In a second preferred embodiment of the present invention, the compound of formula (I) is selected from compounds of formula (I-b)

wherein

R_(1b) is selected from a group consisting of an oxygen-containing heterocyclic ring.

Preferably, R_(1b) is selected from a group consisting of tetrahydrofuryl. More preferably, Rib is 2-tetrahydrofuryl.

In a third preferred embodiment, the use according to the present invention corresponds to a use of a compound of formula (I) as an internal donor in a Ziegler-Natta catalyst,

wherein R₁ is selected from a group consisting of H, methyl, CH₂OR₂ and an oxygen-containing heterocyclic ring; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.

In a fourth preferred embodiment, the use according to the present invention corresponds to a use of a compound of formula (I) as an internal donor in a Ziegler-Natta catalyst,

wherein R₁ is selected from a group consisting of H, CH₂OR₂ and an oxygen-containing heterocyclic ring; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.

The term “oxygen-containing heterocyclic ring” refers a cyclic structure containing an oxygen as part of the ring with 4 to 7 ring atoms, wherein the other ring atoms are preferably carbon. The oxygen-containing heterocyclic ring is preferably a 5 to 6 membered ring comprising one oxygen atom as a member of the ring. The oxygen-containing heterocyclic ring may be saturated, partially unsaturated, unsaturated or aromatic; preferably the oxygen-containing heterocyclic ring is saturated. Preferably, the oxygen-containing heterocyclic ring is unsubstituted. In particular, the oxygen-containing heterocyclic ring is selected from a group consisting of tetrahydrofuryl, more preferably it is 2-tetrahydrofuryl.

In a particular example of the invention the compound of formula (I) is selected from a group consisting of di(2-tetrahydrofuryl)methane (DTHFM), 1,1-di(2-tetrahydrofuryl)ethane (DTHFE), and tris(tetrahydrofuran-2-yl)methane (FFHFM). Among the aforementioned compounds, DTHFM and FFHFM are particularly preferred.

It has been surprisingly found that by using the present internal donor in a Ziegler-Natta catalyst, especially for ethylene (co)polymerization, in particular for producing ethylene (co)polymer in a multi-stage process, it possible to produce multimodal polyethylene having desirable molecular weight, molecular weight distribution (MWD) and chemical composition distribution (CCD).

The improvements, such as the increase in molecular weight and/or the narrowing of MWD, are not made at the expense of the productivity of the catalyst. Instead, the productivity remains at an acceptable level.

(A) Ziegler-Natta Catalyst Component

Provided herein is a Ziegler-Natta catalyst component for olefin polymerization, especially for ethylene (co)polymerization, in particular for producing ethylene (co)polymer in a multi-stage process, comprising an internal donor selected from compounds of formula (I)

wherein

R₁ is selected from a group consisting of H, a linear or branched C₁₋₇-alkyl, CH₂OR₂ and an oxygen-containing heterocyclic ring; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.

Preferably, R₁ is selected from a group consisting of H, a linear or branched C₁₋₅-alkyl, and tetrahydrofuryl. More preferably, R₁ is selected from a group consisting of H, C₁₋₃-alkyl, and 2-tetrahydrofuryl, and still more preferably R₁ is selected from a group consisting of H, methyl, and 2-tetrahydrofuryl.

Preferred embodiments of the present Ziegler-Natta catalyst component are described in the dependent claims as well as in the following description.

In a first example of the Ziegler-Natta catalyst component, the compound of formula (I) is selected from compounds of formula (I-a)

wherein

R_(1a) is selected from a group consisting of H, C₁₋₃-alkyl and CH₂OR₂; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group

Preferably, R_(1a) is selected from a group consisting of H and methyl.

In a second example of the Ziegler-Natta catalyst component, the compound of formula (I) is selected from compounds of formula (I-b)

wherein

R_(1b) is selected from a group consisting of an oxygen-containing heterocyclic ring.

Preferably, R_(1b) is selected from a group consisting of tetrahydrofuryl. More preferably, Rib is 2-tetrahydrofuryl.

In a third example of the Ziegler-Natta catalyst component, the compound of formula (I) is

wherein

R₁ is selected from a group consisting of H, methyl, CH₂OR₂ and an oxygen-containing heterocyclic ring; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.

In a fourth example of the Ziegler-Natta catalyst component, the compound of formula (I) is

wherein

R₁ is selected from a group consisting of H, CH₂OR₂ and an oxygen-containing heterocyclic ring; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.

In a particular example the compound of formula (I) is selected from a group consisting of di(2-tetrahydrofuryl)methane (DTHFM), 1,1-di(2-tetrahydrofuryl)ethane (DTHFE), and tris(tetrahydrofuran-2-yl)methane (FFHFM). Among the aforementioned compounds, DTHFM and FFHFM are particularly preferred.

Provided herein is also a Ziegler-Natta catalyst component as herein described.

The term “Ziegler-Natta catalyst component” as used herein and hereafter refers to a catalyst component, also called a procatalyst, of a Ziegler-Natta catalyst. Ziegler-Natta catalyst component of the present invention comprises at least a transition metal compound and an internal donor.

In particular, it refers to a catalyst component formed from (ii) a compound of a transition metal of Group 4 to 6 of the Periodic Table (IUPAC, Nomenclature of Inorganic Chemistry, 2005), (iii) a compound of a metal of Group 1 to 3 of the Periodic Table (IUPAC, 2005), (iv) optionally a compound of an element of Group 13 or 14 of the Periodic Table (IUPAC, 2005), and (i) an internal donor as herein defined.

Internal Donor (i)

The term “internal donor”, also known as internal electron donor, as used herein and hereafter refers to a compound being part of the Ziegler-Natta catalyst component, i.e. added during the synthesis of the Ziegler-Natta catalyst component and typically acting as an electron donor in the Ziegler-Natta catalyst system.

The internal donor is a part of the Ziegler-Natta catalyst component and is added into said Ziegler-Natta catalyst components during the synthesis thereof.

The loading (during the synthesis) molar ratio of internal donor (ID) to the compound of a metal of Group 1 to 3 (iii), in particular Mg, (ID/Mg), is preferably from 0.010 to 0.300 mol/mol and more preferably from 0.030 to 0.250 mol/mol and even more preferably from 0.040 to 0.120 mol/mol.

Other Compounds of the Ziegler-Natta Catalyst Component

In addition to the internal donor (i), the Ziegler-Natta catalyst component further comprises

-   -   (ii) a compound of a transition metal of Group 4 to 6 of the         Periodic Table (IUPAC, Nomenclature of Inorganic Chemistry,         2005);     -   (iii) a compound of a metal of Group 1 to 3 of the Periodic         Table (IUPAC, 2005); and     -   (iv) optionally, a compound of Group 13 element of the Periodic         Table (IUPAC, 2005).

The Ziegler-Natta catalyst component is typically solid. The solid Ziegler-Natta catalysts component may be formed without using any external support material or it can be a solid Ziegler-Natta catalyst component supported on an external support material.

The solid supported Ziegler-Natta catalyst component of the present invention comprises

-   -   (i) an internal donor selected from compounds of formula (I) as         discussed herein;     -   (ii) a compound of a transition metal of Group 4 to 6 of the         Periodic Table (IUPAC, Nomenclature of Inorganic Chemistry,         2005), in particular a titanium compound;     -   (iii) a compound of Group 1 to 3 metal of the Periodic Table         (IUPAC, 2005), in particular a magnesium compound; and     -   (iv) optionally, a compound of Group 13 element of the Periodic         Table (IUPAC, 2005), in particular an aluminium compound;

wherein the components (i) to (iv), when present, are supported on a solid support.

The solid support can be selected from a group consisting of an inorganic oxide solid support, such as silica, alumina, titania, silica-alumina, and silica-titania, and a Mg-based solid support, such as a MgCl₂-based solid support. Preferably, the solid support is silica or a Mg-based solid support, such as a MgCl₂-based solid support, more preferably the solid support is solid support of particles of MgCl₂*mROH adduct, wherein R in the adduct MgCl₂*mROH is a linear or branched C₁₋₁₂-alkyl group, and m is 0 to 6, preferably 1 to 6, more preferably m is 1 to 4.

The volume-based median particle size (D_(v0.5)) of a silica support is typically from 2 to 500 μm, preferably 5 to 200 μm, more preferably 10 to 100 μm. However, it has turned out that special advantages can be obtained if the support has a D_(v0.5) 0.5 particle size from 5 to 30 μm, preferably from 7 to 20 μm, more preferably from 8 to 15 μm. Alternatively, the silica support may have a D_(v0.5) particle size of from 20 to 80 μm, preferably from 20 to 30 μm. Examples of suitable support materials include, for instance, ES747JR, produced and marketed by Ineos Silicas (former Crossfield), and SP9-491, produced and marketed by Grace.

The catalyst component can be prepared by sequentially contacting the carrier with the above mentioned compounds, as described e.g. in EP0688794 A1 and WO99/51646 A1. Alternatively, it can be prepared by first preparing a solution from the components and then contacting the solution with a carrier, as described in WO01/55230 A1.

Alternatively, the catalyst component used in the present invention may be supported on a Mg-based solid support, in particular MgCl₂. Thus, the catalyst comprises a titanium compound and optionally a Group 13 element compound, for example an aluminium compound, on a magnesium dihalide, such as magnesium dichloride. A group of such Ziegler-Natta catalyst components comprise a titanium compound together with a magnesium halide compound acting as a support. Such catalysts are disclosed, for instance, in WO2005/118655 A1, EP0810235 A2, WO2014/096296 A1 and WO2016/097193 A1.

The catalyst may, for example, be prepared by contacting spheroidal or granular MgCl₂*mROH, like MgCl₂*mEtOH, carrier material with an internal electron donor, selected from compounds of formula (I), in the beginning of the catalyst synthesis, i.e. prior to a treatment with the titanium compound (e.g. TiCl₄) or even prior to a treatment of the MgCl₂*mEtOH carrier material with a Group 13 element compound and by finally recovering the solid catalyst component.

The median particle size D_(v0.5) of a Mg-based solid support is typically from 2 to 500 μm, preferably 5 to 200 μm, more preferably 10 to 100 μm. However, it has turned out that special advantages can be obtained if the support has a D_(v0.5) particle size from 5 to 30 μm, preferably from 7 to 25 μm, more preferably from 8 to 20 μm, or even from 8 to 15 μm. Alternatively, the support may have a D_(v0.5) particle size of from 20 to 80 μm, preferably from 20 to 30 μm. MgCl₂*mROH can be prepared by methods described in prior art.

Preparation methods of MgCl₂*mROH carrier are described in several patents e.g. in EP0376936 B1, EP0424049 B1, EP0655073 B1, U.S. Pat. No. 4,071,674 and EP0614467 B1, which are incorporated herein by reference.

Solid Ziegler-Natta catalyst components may alternatively be formed without using any external support material, like silica, alumina or separately prepared Mg-based solid support, onto which active catalyst component are loaded. Instead, a solid catalyst is formed by a method where all active catalyst compounds are contacted and/or reacted in liquid form with each other, and, after that, the solid catalyst is formed.

In an embodiment of the present invention, the Ziegler-Natta catalyst component comprises

-   -   (i) an internal donor selected from compounds of formula (I) as         discussed herein;     -   (ii) a Group 4 to 6 metal, preferably a Group 4 metal, more         preferably Ti, content (determined by ICP Analysis) in the range         of 1.0 wt % to 15.0 wt %, preferably 2.5 wt % to 12.0 wt %, more         preferably 3.5 wt % to 9.5 wt % of the total weight of the         Ziegler-Natta catalyst component;     -   (iii) a Group 1 to 3, preferably a Group 2 metal, more         preferably Mg, content (determined by ICP Analysis) in the range         of 5.0 wt % to 30.0 wt %, preferably 9.0 wt % to 22.0 wt %, more         preferably 12.5 wt % to 18.5 wt % of the total weight of the         Ziegler-Natta catalyst component;     -   (iv) an Al content (determined by ICP Analysis) in the range of         0.0 wt % to 3.0 wt %, preferably 0.0 wt % to 2.6 wt %, more         preferably 0.0 wt % to 1.8 wt % of the total weight of the         Ziegler-Natta catalyst component.

Further, the Ziegler-Natta catalyst component according to an embodiment of the present invention has a median particle size D_(v0.5) in the range of 2 to 100 μm, preferably 5 to 30 μm, more preferably 8 to 20 μm, even more preferably 8 to 15 μm.

Transition Metal Compound of Group 4 to 6 (ii)

The compound of a transition metal of Group 4 to 6 of the Periodic Table (IUPAC, Nomenclature of Inorganic Chemistry, 2005) is preferably a compound of a transition metal of Group 4 of the Periodic Table (IUPAC, 2005) or a vanadium compound, more preferably a titanium or vanadium compound, even more preferably a titanium compound, yet even more preferably a halogen-containing titanium compound, most preferably a chlorine-containing titanium compound.

In a particularly preferred embodiment, the titanium compound is a halogen-containing titanium compound of the formula Hal_(y)Ti(OAlk)_(4-y), wherein Alk is a C₁₋₂₀-alkyl group, preferably a C₂₋₁₀-alkyl group, and more preferably a C₂₋₈-alkyl group, Hal is halogen, preferably chlorine and y is 1, 2, 3 or 4, preferably 3 or 4 and more preferably 4.

Suitable titanium compounds include trialkoxytitanium monochlorides, dialkoxytitanium dichloride, alkoxytitanium trichloride, and titanium tetrachloride. Preferably, titanium tetrachloride is used.

The amount of the compound of Group 4 to 6 in the Ziegler-Natta catalyst component is preferably such that the content of the Group 4 to 6 metal, preferably Group 4 metal, more preferably Ti (determined by ICP Analysis) is in the range of 1.0 wt % to 15.0 wt %, preferably 2.5 wt % to 12.0 wt %, more preferably 3.5 wt % to 9.5 wt % of the total weight of the Ziegler-Natta catalyst component. The amount of the compound of Group 4 to 6 metal is determined by ICP Analysis as described in the Experimental part.

Metal Compound of Group 1 to 3 Metal (iii)

The compound of Group 1 to 3 metal is preferably a compound of Group 2 metal of the Periodic Table (IUPAC, Nomenclature of Inorganic Chemistry, 2005), more preferably a magnesium compound.

The amount of the metal compound of Group 1 to 3 in the Ziegler-Natta catalyst component is preferably such that a Group 1 to 3 metal, preferably a Group 2 metal, more preferably Mg, content is in the range of 5.0 wt % to 30.0 wt %, preferably 9.0 wt % to 22.0 wt %, more preferably 12.5 wt % to 18.5 wt % of the total weight of the Ziegler-Natta catalyst component. The amount of the metal compound of Group 1 to 3 is determined by ICP Analysis as described in the Experimental part.

In a particular example the metal compound of Group 1 to 3 is provided in the form of a MgCl₂-based solid support, preferably solid support particles of MgCl₂*mROH adduct, wherein R in the adduct MgCl₂*mROH is a linear or branched C₁₋₁₂-alkyl group, and m is 0 to 6, preferably 1 to 6, more preferably 1 to 4.

Preferably, the final solid Ziegler-Natta catalyst component particles have a median particle size D_(v0.5) in the range of 2 to 100 μm, preferably 5 to 30 μm, more preferably 8 to 20 μm, even more preferably 8 to 15 μm.

Compound of Group 13 Element (iv)

The optional compound of Group 13 element of the Periodic Table (IUPAC, Nomenclature of Inorganic Chemistry, 2005) is preferably an aluminium compound.

Particularly preferably the aluminium compound is an aluminium compound of the formula Al(alkyl)_(x)Hal_(3-x) (II), wherein each alkyl is independently an C₁₋₁₂-alkyl group, preferably C₁₋₈-alkyl group, more preferably C₁₋₈-alkyl group, Hal is halogen, preferably chlorine and 1<x≤3. The alkyl group can be linear, branched or cyclic, or a mixture of such groups.

Preferred aluminium compounds are alkylaluminium dichlorides, dialkylaluminium chlorides or trialkylaluminium compounds, for example dimethylaluminium chloride, diethylaluminium chloride, di-isobutylaluminium chloride, and triethylaluminium or mixtures thereof. Most preferably, the aluminium compound is a trialkylaluminium compound, especially triethylaluminium.

The amount of the compound of Group 13 element in the Ziegler-Natta catalyst component is preferably such that the Group 13 element, preferably Al, content is in the range of 0 wt % to 3.0 wt %, preferably 0 wt % to 2.6 wt %, more preferably 0 wt % to 1.8 wt % of the total weight of the Ziegler-Natta catalyst component. The amount of the compound of Group 13 element is determined by ICP Analysis as described in the Experimental part.

The internal donor is a part of the Ziegler-Natta catalyst component and is added to said Ziegler-Natta catalyst component during the synthesis thereof.

The molar loading ratio (in the synthesis) of internal donor (ID) to the metal of Group 1 to 3 (iii), in particular Mg (ID/Mg), is preferably from 0.010 to 0.300 mol/mol and more preferably from 0.030 to 0.250 mol/mol and even more preferably from 0.040 to 0.120 mol/mol.

The final Ziegler-Natta catalyst component typically has:

a Mg/Ti mol/mol ratio from 2.0 to 15.0, preferably from 2.5 to 12.0, more preferably from 2.8 to 7.0;

an Al/Ti mol/mol ratio from 0 to 1.0, preferably from 0 to 0.8, more preferably from 0 to 0.5; and

a Cl/Ti mol/mol ratio from 5.0 to 30.0, preferably from 6.0 to 27.0, more preferably from 9.0 to 16.0.

Method for Producing the Ziegler-Natta Catalyst Component

Generally, the present Ziegler-Natta catalyst component as defined herein is produced by adding the present internal donor, i.e. compound of formula (I), to a process of preparing the Ziegler-Natta catalyst component. This may be accomplished by manners and under conditions that are well known to the person skilled in the art of making Ziegler-Natta catalysts.

Accordingly, provided herein is a method for producing a Ziegler-Natta catalyst component, in particular a Ziegler-Natta catalyst component as defined herein, comprising adding internal donor of formula (I) defined herein to a process of preparing the Ziegler-Natta catalyst component.

A solid Ziegler-Natta catalyst component can, for example, be prepared by sequentially contacting a solid support, such as silica, alumina or separately prepared Mg-based solid support, such as MgCl₂-based solid support, with the above-mentioned compounds, as described in EP0376936 A1, EP0688794 A1 or WO99/51646 A1. Alternatively, it can be prepared by first preparing a solution from the components and then contacting the solution with a solid support, as described in WO01/55230 A1.

In a particular example of the present method, the method for producing the Ziegler-Natta catalyst component comprises the steps of

-   -   (M-a) providing a solid support, preferably MgCl₂-based solid         support, more preferably solid support particles of MgCl₂*mROH         adduct, wherein R in the MgCl₂*mROH adduct is a linear or         branched C₁₋₁₂-alkyl group, and m is 0 to 6, preferably 1 to 6,         more preferably 1 to 4;     -   (M-b) pre-treating the solid support particles of step (M-a)         with a compound of Group 13 element;     -   (M-c) treating the pre-treated solid support particles of step         (M-b) with a transition metal compound of Group 4 to 6;     -   (M-d) recovering the Ziegler-Natta catalyst component;

wherein the solid support is contacted with an internal organic compound of formula (I) or mixtures therefrom before treating the solid support in step (M-c).

Preferably, the compound of formula (I), as defined herein, is added to the catalyst mixture before, during or after the pre-treating of the solid support with the Group 13 element compound, but before treating it with the compound of a transition metal of Group 4 to 6.

Solid Ziegler-Natta catalyst components may also be formed without using any external support material, like silica, alumina or separately prepared Mg-based solid support, onto which active catalyst component are loaded. In this case, a solid catalyst is formed by a method where all active catalyst compounds are contacted and/or reacted in liquid form with each other, and after that the solid catalyst is formed. The solid Ziegler-Natta catalyst components may be formed via emulsion-solidification or via precipitation method. Whether a Ziegler-Natta catalyst component is formed via emulsion-solidification or via precipitation method depends on the conditions, especially on the temperature used during contacting the compounds. In the emulsion-solidification method the compounds of the Ziegler-Natta catalyst component form a dispersed, i.e. a discontinuous phase in the emulsion of at least two liquid phases. The dispersed phase, in the form of droplets, is solidified from the emulsion, wherein the Ziegler-Natta catalyst component in the form of solid particles is formed. The principles of preparation of these types of catalysts are given e.g. in WO2003/106510 A1, WO2013/098139 A1 and WO2014/096297 A1.

Ziegler-Natta Catalyst

Accordingly further provided herein is a Ziegler-Natta catalyst for olefin polymerization, in particular for ethylene (co)polymerization, comprising the catalyst component as herein defined wherein the catalyst component comprises an internal donor selected from compounds of formula (I). Accordingly further provided herein is use of a Ziegler-Natta catalyst for olefin polymerization, in particular for ethylene (co)polymerization, comprising a Ziegler-Natta catalyst component comprising an internal donor selected from compounds of formula (I)

wherein

R₁ is selected from a group consisting of H, a linear or branched C₁₋₇-alkyl, CH₂OR₂ and oxygen-containing heterocyclic ring; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.

Preferably, R₁ is selected from a group consisting of H, a linear or branched C₁₋₅-alkyl, and tetrahydrofuryl. More preferably, R₁ is selected from a group consisting of H, and 2-tetrahydrofuryl, and still more preferably, R₁ is selected from a group consisting of H, methyl, and 2-tetrahydrofuryl.

Preferably, R₁ is selected from a group consisting of H, methyl, and tetrahydrofuryl. More preferably, R₁ is selected from a group consisting of H, methyl, and 2-tetrahydrofuryl.

Preferred embodiments of the use of the present Ziegler-Natta catalyst are described in the dependent claims as well as in the following description.

In a first example of the Ziegler-Natta catalyst and use thereof, the compound of formula (I) is selected from compounds of formula (I-a)

wherein

R_(1a) is selected from a group consisting of H, C₁₋₃-alkyl and CH₂OR₂; and

R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.

Preferably, R_(1a) is selected from a group consisting of H and methyl.

In a second example of the Ziegler-Natta catalyst, the compound of formula (I) is selected from compounds of formula (I-b)

wherein

R_(1b) is selected from a group consisting oxygen-containing heterocyclic ring.

Preferably, R_(1b) is selected from a group consisting of tetrahydrofuryl. More preferably, Rib is 2-tetrahydrofuryl.

In a third example of the Ziegler-Natta catalyst component, the compound of formula (I) is

wherein

R₁ is selected from a group consisting of H, methyl, CH₂OR₂ and an oxygen-containing heterocyclic ring; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.

In a fourth example of the Ziegler-Natta catalyst component, the compound of formula (I) is

wherein

R₁ is selected from a group consisting of H, CH₂OR₂ and an oxygen-containing heterocyclic ring; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.

In a particular example the compound of formula (I) is selected from a group consisting of di(2-tetrahydrofuryl)methane (DTHFM), 1,1-di(2-tetrahydrofuryl)ethane (DTHFE), and tris(tetrahydrofuran-2-yl)methane (FFHFM). Among the aforementioned compounds DTHFM and FFHFM are particularly preferred.

Provided is also a Ziegler-Natta catalyst as herein disclosed.

In particular the present Ziegler-Natta catalyst comprises

-   -   (A) a Ziegler-Natta catalyst component as defined herein;     -   (B) a cocatalyst selected from element compounds of Group 13 of         the Periodic Table (IUPAC, 2005); and     -   (C) optionally an external donor.

(B) Cocatalyst (II)

A Ziegler-Natta catalyst is typically used together with a cocatalyst, also known as activator. Suitable cocatalysts are I compounds of element of Group 13 of the Periodic Table (IUPAC, 2005), typically Group 13 element C₁₋₁₆-alkyl compounds and especially aluminium C₁₋₁₆-alkyl compounds. These compounds include trialkylaluminium compounds, such as trimethylaluminium, triethylaluminium, tri-isobutylaluminium, trihexylaluminium and tri-n-octylaluminium, alkyl aluminium halides, such as ethylaluminium dichloride, diethylaluminium chloride, ethylaluminium sesquichloride, dimethylaluminium chloride and the like. Especially preferred activators are trialkylaluminiums, of which triethylaluminium, trimethylaluminium and tri-isobutylaluminium are particularly used.

The amount in which the cocatalyst is used depends on the specific catalyst and the cocatalyst. Typically, e.g. triethylaluminium is used in such amount that the molar ratio of aluminium to the transition metal, like Al/Ti, is from 1 to 1000, preferably from 3 to 100 and in particular from about 5 to about 30 mol/mol.

(C) External Donor

The catalyst of the invention may also comprise an external donor. External donors that can be used include ether compounds, typically tetrahydrofuran, siloxane or silane type of external donors and/or alkyl halides as are known from the prior art. External donors are also called external electron donors. External electron donors are not part of the solid catalyst component, but are fed to the polymerization process as a separate component.

Polymerization of Olefins

The present Ziegler-Natta catalyst components as defined herein, in particular Ziegler-Natta catalysts as defined herein are intended for polymerizing olefins, preferably ethylene, optionally with C₂₋₂₀ comonomers.

Accordingly provided here in is the use of Ziegler-Natta catalyst component as defined herein or a Ziegler-Natta catalyst as defined herein in olefin polymerization, preferably ethylene (co)polymerization, optionally with C₂₋₂₀ comonomers.

Furthermore, provided herein is a method of olefin polymerization, in particular of ethylene (co) polymerization, which comprises introducing into a polymerization reactor a Ziegler-Natta catalyst, wherein the Ziegler-Natta catalyst comprises a Ziegler-Natta catalyst component as defined herein.

Preferably, a Ziegler-Natta catalyst component as defined herein or a Ziegler-Natta catalyst as defined herein is used in ethylene (co)polymerization, optionally with one or more comonomers. Commonly used comonomers in ethylene polymerization are a-olefin comonomers. The a-olefin comonomers are preferably selected from C₃₋₂₀-α-olefins, more preferably from C₄₋₁₀-α-olefins, such as 1-butene, isobutene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene and 1-decene, as well as dienes, such as butadiene, 1,7-octadiene and 1,4-hexadiene, or cyclic olefins, such as norbornene, and any mixtures thereof. Most preferably, the comonomer is 1-butene and/or 1-hexene.

The catalyst of the present invention allows for the production of a wide range of polyethylene (co)polymers. Thus, production of high density, medium density and low density ethylene (co)polymers is possible.

If copolymers are the desired end-products, the comonomer content of the ethylene copolymers can vary in wide ranges depending on the desired polymer properties. Thus, the comonomer content can vary from 0.1 wt % to 20 wt %, preferably 0.5 to 15 wt % and more preferably from 1.0 to 10 wt %.

Further provided herein is a process for producing ethylene homo- or copolymers, comprising the steps of

-   -   (P-a) introducing a Ziegler-Natta catalyst component as defined         herein into a polymerization reactor;     -   (P-b) introducing a cocatalyst capable of activating said         procatalyst into the polymerization reactor;     -   (P-c) introducing ethylene, optionally C₃-C₂₀ α-olefin         comonomers, and optionally hydrogen into the polymerization         reactor; and     -   (P-d) maintaining said polymerization reactor in such conditions         as to produce an ethylene homo- or copolymer.

The catalyst may be transferred into the polymerization zone by any means known in the art. It is thus possible to suspend the catalyst in a diluent and maintain it as homogeneous slurry. Especially preferred it is to use oil having a viscosity from 20 to 1500 mPa·s as diluent, as disclosed in WO2006/063771 A1. It is also possible to mix the catalyst with a viscous composition of grease and oil and feed the resultant paste into the polymerization zone. Further still, it is possible to let the catalyst settle and introduce portions of thus obtained catalyst mud into the polymerization zone in a manner disclosed, for instance, in EP0428054 A1.

The polymerization process used according to the present invention comprises at least one gas phase reactor, or at least one slurry reactor or a combination of at least one slurry and at least one gas phase reactor.

The polymerization in slurry usually takes place in an inert diluent, typically a hydrocarbon diluent such as methane, ethane, propane, n-butane, isobutane, pentanes, hexanes, heptanes, octanes etc., or their mixtures. Preferably, the diluent is a low-boiling hydrocarbon having from 1 to 4 carbon atoms or a mixture of such hydrocarbons. An especially preferred diluent is propane, possibly containing minor amount of methane, ethane and/or butane.

The temperature in the slurry polymerization is typically from 40 to 115° C., preferably from 60 to 110° C. and in particular from 70 to 100° C. The pressure is from 1 to 150 bar, preferably from 10 to 100 bar.

The slurry polymerization may be carried out in any known reactor used for slurry polymerization. Such reactors include a continuous stirred tank reactor and a loop reactor. It is especially preferred to conduct the polymerization in loop reactor. Hydrogen is fed, optionally, into the reactor to control the molecular weight of the polymer as known in the art.

Furthermore, one or more alpha-olefin comonomers may be added to the reactor to control the density and morphology of the polymer product. The actual amount of such hydrogen and comonomer feeds depends on the desired melt index (or molecular weight) and density (or comonomer content) of the resulting polymer.

The polymerization in gas phase may be carried out in a fluidized bed reactor, in a fast-fluidized bed reactor or in a settled bed reactor or in any combination of these.

Typically, the fluidized bed or settled bed polymerization reactor is operated at a temperature within the range of from 50 to 100° C., preferably from 65 to 90° C. The pressure is suitably from 10 to 40 bar, preferably from 15 to 30 bar.

In addition, antistatic agent(s) may be introduced into the slurry and/or gas phase reactor if needed.

The process may further comprise pre- and post-reactors.

The polymerization steps may be preceded by a pre-polymerization step. The pre-polymerization step may be carried out in slurry or in gas phase. Preferably, pre-polymerization is carried out in slurry, and especially in a loop reactor. The temperature in the pre-polymerization step is typically from 0 to 90° C., preferably from 20 to 80° C. and more preferably from 30 to 70° C.

The pressure is not critical and is typically from 1 to 150 bar, preferably from 10 to 100 bar.

The polymerization may be carried out continuously or batch-wise, preferably the polymerization is carried out continuously.

A preferred multi-stage process for producing ethylene (co)polymers according to the invention comprises a slurry phase polymerization stage and a gas phase polymerization stage. Each stage can comprise one or more polymerization reactors. One suitable reactor configuration comprises one to two slurry reactors, preferably loop reactors and one gas phase reactor. Such polymerization configuration is described e.g. in patent literature, such as in WO92/12182 A1 and WO96/18662 A1 of Borealis and known as Borstar technology.

In a first example of the present process, polymerizing olefins is accomplished in a multi-stage polymerization process comprising at least one gas phase reactor for producing ethylene (co)polymers.

In a second example of the present process, polymerizing olefins is accomplished in a multi-stage polymerization process comprising at least one slurry reactor, preferably two slurry reactors, and one gas phase reactor.

Polymer Properties

By utilizing the present internal donor in a Ziegler-Natta catalyst component in a polymerization process according to the present invention it is possible to produce ethylene (co)polymers having desirable molecular weight, molecular weight distribution (MWD) and chemical composition distribution (CCD) while keeping the productivity on a good level as shown by the below examples.

The molecular weight, molecular weight distribution (MWD) and chemical composition distribution (CCD) of the produced polymer can be optimized by utilization of the present internal donors in Ziegler-Natta catalysts.

Further, the improvements, such as the increase in molecular weight, the improvement in chemical composition distribution and the narrowing of MWD, are not made at the expense of the productivity of the catalyst, but the productivity remains at an acceptable level. Thus, the performance of Ziegler-Natta catalysts comprising the present internal donors renders the improvements, such as the increase in molecular weight, the improvement in chemical composition distribution and the narrowing of MWD, which are not obtained at the expense of the productivity of the catalyst, but the productivity remains at an acceptable level.

Especially an optimal combination of hydrogen response, MWD, comonomer response, chemical composition distribution (CCD), catalyst activity and productivity makes the utilization of the present internal donors in Ziegler-Natta catalysts very attractive for producing polyethylene (co)polymers.

The advantages of the present invention are shown in the experimental part and in the figures:

FIG. 1 shows the polydispersity index (PDI) vs. molecular weight of inventive examples (IE1-IE4) and comparative examples CE1-CE9.

FIG. 2 shows the melting temperature vs. comonomer content inventive examples (IE1-IE4) and comparative examples CE1-CE9.

FIG. 3 shows activity level vs. molecular weight of inventive examples (IE1-IE4) and of comparative examples CE1-CE9.

EXPERIMENTAL PART

Analytical Methods

Al, Mq, Ti Contents in a Catalyst Component by ICP-OES

The sample consisting of dry catalyst component powder is mixed so that a representative test portion can be taken. Approximately 20-50 mg of material is sampled in inert atmosphere into a 20 mL volume vial and the exact weight of powder recorded.

A test solution of known volume (V) is prepared in a volumetric flask as follows. Sample digestion is performed in the cooled vial by adding a small amount of deionized and distilled (DI) water (5% of V), followed by adding concentrated nitric acid (65% HNO₃, 5% of V). The mixture is transferred into a volumetric flask. The solution diluted with DI water up to the final volume V, and left to stabilise for two hours.

The elemental analysis of the resulting aqueous samples is performed at room temperature using a Thermo Elemental iCAP 6300 Inductively Coupled Plasma—Optical Emission Spectrometer (ICP-OES). The instrument is calibrated for Al, Ti and Mg using a blank (a solution of 5% HNO₃) and six standards of 0.5 ppm, 1 ppm, 10 ppm, 50 ppm, 100 ppm and 300 ppm of Al, Ti and Mg in solutions of 5% HNO₃ DI water. Curvelinear fitting and 1/concentration weighting is used for the calibration curve.

Immediately before analysis the calibration is verified and adjusted (instrument function named “re-slope”) using the blank and a 300 ppm Al, 100 ppm Ti, Mg standard. A quality control sample (QC; 20 ppm Al and Ti, 50 ppm Mg in a solution of 5% HNO₃ in DI water) is run to confirm the re-slope. The QC sample is also run after every 5^(th) sample and at the end of a scheduled analysis set.

The content of magnesium is monitored using the 285.213 nm line and the content for titanium using 336.121 nm line. The content of aluminium is monitored via the 167.079 nm line, when Al concentration in test portion is between 0-10 wt % and via the 396.152 nm line for Al concentrations above 10 wt %.

The reported values are an average of results of three successive aliquots taken from the same sample and are related back to the original catalyst sample based on input into the software of the original weight of test portion and the dilution volume.

CI Content in a Catalyst Component by Potentiometric Titration

Chloride content of catalyst components is determined by titration with silver nitrate. A test portion of 50-200 mg of a catalyst component is weighed under nitrogen in a septum-sealed vial. A solution of 1 part of concentrated HNO₃ (68%, analytical grade) and 4 parts of deionized and distilled (DI) water are added to the sample in an aliquot of 2.5 mL using a syringe. After the reaction completion and dissolution of the catalyst component material, the solution is transferred into a titration cup using an excess of DI water. The solution is then immediately titrated with a commercially certified solution of 0.1 M AgNO₃ in a Mettler Toledo T70 automatic titrator. The titration end-point is determined using an Ag-electrode. The total chloride amount is calculated from the titration and related to the original sample weight.

Volatiles in a Catalyst Component by GC-MS

A test solution using a 40-60 mg test portion of catalyst component powder is prepared by liquid-liquid extraction of the sample and internal standard in water and dichloromethane: first, 10 mL of dichloromethane are added to the test portion, followed by addition of 1 mL of the internal standard solution (dimethyl pimelate, 0.71 vol % in deionized water) using a precision micro-syringe. The suspension is sonicated for 30 min and left undisturbed for phase separation. A portion of the test solution is taken from the organic phase and filtered using a 0.45 μm syringe filter.

For the calibration, five standard stock solutions with different analyte concentrations are prepared by dosing five increasing portions of analyte standard materials accurately into volumetric flasks and filling up to mark with methanol. For the preparation of the calibration samples, aliquots of 200 μL from the stock solutions are extracted with the aqueous ISTD solution and dichloromethane in the same volume ratios as for the samples. The analyte amount in the final calibration samples ranges from 0.1 mg to 15 mg.

The measurement is performed using an Agilent 7890B Gas Chromatograph equipped with an Agilent 5977A Mass Spectrometer Detector. The separation is achieved using a ZB-XLB-HT Inferno 60 m×250 μm×0.25 μm column (Phenomenex) with midpoint backflush through a three channel auxiliary EPC and a pre-column restriction capillary of 3 m×250 μm×0 μm. The initial oven temperature is 50° C. and the hold time is 2 min. The oven ramp consists of a first stage of 5° C./min to 150° C. and a second stage of 30° C./min to 300° C. followed by a 1 min post-run backflush at 300° C.

The inlet operates in split mode. Injection volume is 1 μL, inlet temperature 280° C., septa purge 3 mL/min, total flow 67.875 mL/min and split ratio 50:1. Carrier gas is 99.9996% He with pre-column flow of 1.2721 mL/min and additional flow of 2 mL/min from the backflush EPC to the analytical column. The MS detector transfer line is kept at 300° C. The MSD is operated in Electron Impact mode at 70 eV and Scan mode ranging from 15-300 m/z.

The signal identities are determined by retention times (heptane 4.8, toluene 6.3, dimethyl-pimelate 23.2) and target ion m/z (heptane 71.1, toluene 91.1, dimethyl pimelate 157.1). Additionally, qualifier ions are used for confirmation of the identification (heptane, toluene). The target ion signals of each analyte and the internal standard are integrated and compared to calibration curve, established in the beginning of each run with the five calibration samples. The calibration curves for the response ratios are linear without sample concentration weighting. A quality control sample is used in each run to verify the standardization. All test solutions are run in two replicate runs. The mass of the test portion is used for calculating the analyte concentration in the sample for both replicates and the result reported as the average.

Polymer Melting and Crystallization Properties by DSC

Polymer Differential Scanning calorimetry analysis (DSC) is performed using a Mettler Toledo DSC2 on 5-10 mg samples. The polymer powder or pellet cut or MFR string cut sample is placed in a 40 μL aluminium pan, weighed to the nearest 0.01 mg and the pan is sealed with a lid. DSC is run according to ISO 11357-3 or ASTM D3418 in a heat/cool/heat run cycle with a scan rate of 10° C./min. The flow of nitrogen purge gas is set to 50-80 mL/min. The temperature range of the first heating run is 30° C. to 180° C. The temperature range of the cooling run and the second heating run is 180° C. to 0° C. (or lower). The isotherm times for the first heating run and the cooling run are 5 min. The first melting run is used to remove the thermal history of the sample. Crystallization temperature (T_(c)) is determined from the cooling run, while main melting temperature (T_(m)), degree of crystallinity (Cryst. %) and heat of melting (H_(m)) are determined from the second heating run.

Polymer Melt Flow Rate

The melt flow rates are measured in accordance with ISO 1133 at 190° C. and under given load and is indicated in units of grams/10 minutes. The melt flow rate is an indication of the molecular weight of the polymer. The higher the melt flow rate, the lower the molecular weight of the polymer.

MFR₂₁: 190° C., 21.6 kg load

Molecular Weight Averages, Molecular Weight Distribution (M_(n), M_(w), M_(z), MWD, PDI)

Molecular weight averages (M_(z), M_(w) and M_(n)), Molecular Weight Distribution (MWD) and its broadness, described by polydispersity index PDI=M_(w)/M_(n) (wherein M_(n) is the number average molecular weight and M_(w) is the weight average molecular weight) are determined by Gel Permeation Chromatography (GPC) according to ISO 16014-1:2003, ISO 16014-2:2003, ISO 16014-4:2003 and ASTM D 6474-12 using the following formulas:

$\begin{matrix} {M_{n} = \frac{\Sigma_{i = 1}^{N}A_{i}}{\Sigma_{i = 1}^{N}\left( {A_{i}/M_{i}} \right)}} & (1) \end{matrix}$ $\begin{matrix} {M_{w} = \frac{\Sigma_{i = 1}^{N}\left( {A_{i} \times M_{i}} \right)}{\Sigma_{i = 1}^{N}A_{i}}} & (2) \end{matrix}$ $\begin{matrix} {M_{z} = \frac{\Sigma_{i = 1}^{N}\left( {A_{i} \times M_{i}^{2}} \right)}{\Sigma_{i = 1}^{N}\left( {A_{i}/M_{i}} \right)}} & (3) \end{matrix}$

For a constant elution volume interval ΔV_(i), where A_(i), and M_(i) are the chromatographic peak slice area and polyolefin molecular weight (MW), respectively associated with the elution volume, V_(i), where N is equal to the number of data points obtained from the chromatogram between the integration limits.

A high temperature GPC instrument, equipped with either infrared (IR) detector (IR4 or IR5 from PolymerChar (Valencia, Spain) or differential refractometer (RI) from Agilent Technologies, equipped with 3× Agilent-PLgel Olexis and lx Agilent-PLgel Olexis Guard columns is used. As the solvent and mobile phase 1,2,4-trichlorobenzene (TCB) stabilised with 250 mg/L 2,6-Di-tert-butyl-4-methyl-phenol) is used. The chromatographic system is operated at 160° C. and at a constant flow rate of 1 mL/min. 200 μL of sample solution is injected per analysis. Data collection is performed using either Agilent Cirrus software version 3.3 or PolymerChar GPC-IR control software.

The column set is calibrated using universal calibration (according to ISO 16014-2:2003) with 19 narrow MWD polystyrene (PS) standards in the range of 0.5 kg/mol to 11500 kg/mol. The PS standards are dissolved at room temperature over several hours. The conversion of the polystyrene peak molecular weight to polyolefin molecular weights is accomplished by using the Mark Houwink equation and the following Mark Houwink constants:

K _(PS)=19×10⁻³ mL/g,η_(PS)=0.655

K _(PE)=39×10⁻³ mL/g,η_(PE)=0.725

K _(PP)=19×10⁻³ mL/g,η_(PP)=0.725

A third order polynomial fit is used to fit the calibration data.

All samples are prepared in the concentration range of 0.5-1 mg/mL and dissolved at 160° C. for 2.5 hours for PP or 3 hours for PE under continuous gentle shaking.

Polymer Comonomer Content (1-Butene) by FTIR

Comonomer content is determined based on Fourier transform infrared spectroscopy (FTIR) using Bruker Tensor 37 spectrometer together with OPUS software.

Approximately 0.3 grams of sample is compression-moulded into films with thickness of 250 μm. Silicone paper is used on both sides of the film. The films are not touched by bare hands to avoid contamination. The films are pressed by using Fontijne Press model LabEcon 300. The moulding is carried out at 160° C. with 2 min pre-heating+2 min light press+1 min under full press. The cooling is done under full press power for 4 minutes.

The butene comonomer content is determined from the absorbance at the wave number of approximately 1378 cm⁻¹ and the reference peak is 2019 cm⁻¹. The analysis is performed using a resolution of 2 cm⁻¹, wave number span from 4000 to 400 cm⁻¹ and the number of sweeps of 128. At least two spectra are obtained from each film.

The comonomer content is determined from a spectrum from the wave number range of 1400 cm⁻¹ to 1330 cm⁻¹. The baseline is determined using the following method: within the set wavenumber range, the highest peak is located and then the minima to the left and to the right of this highest peak. The baseline connects these minima. The absorbance value at the highest peak is divided by the area of the reference peak.

The calibration plot for the method is produced for each comonomer type separately. The comonomer content of an unknown sample needs to be within the range of the comonomer contents of the calibration samples. The comonomer content in the calibration sample materials is pre-determined by NMR-spectrometry.

The comonomer content is calculated automatically by using calibration curve and the following formula:

W _(E) =C ₁ ×A ₀ +C ₀

where

W_(E)=result in wt %

A₀=absorbance of the measured peak (A_(Q)) to the area of the reference peak (A_(R));

C₁=slope of the calibration curve;

C₀=offset of the calibration curve.

The comonomer content is determined from both of the obtained spectra and the value is calculated as the average of these results.

Examples

Comparative Internal Donors

CD1: Di(Furan-2-Yl)Methane(DFM)

Di(furan-2-yl)methane (CAS 1197-40-6), alternatively named Bis(2-furyl)methane, was prepared as described in [a) Chem. Eur. J., 2000, 6, 22, 4091; b) J. Appl. Polym. Sci., 2014, DOI: 10.1002/app.40179]. The product was isolated in 62% yield by vacuum distillation (b.p. 70° C./15 mbar).

¹H NMR (CDCl₃, 400 MHz): δ 7.33 (m, 2H), 6.31 (m, 2H), 6.08 (d, J=3.0 Hz, 2H), 4.00 (s, 2H)

¹³C{¹H} NMR (CDCl₃, 100 MHz): δ 151.5, 141.6, 110.4, 106.4, 27.4.

CD2: 1,1-Di(furan-2-yl)ethane (DFE)

1,1-Di(furan-2-yl)ethane (CAS 51300-81-3), alternatively named 1,1-Bis(2-furyl)ethane or 2,2′-(Ethane-1,1-diyl)difuran, was prepared using slightly modified described method [J. Heterocyclic. Chem., 1991, 28, 991].

To an ice-cooled mixture of 85 mL of ethanol and 50 mL of 12 M HCl 175 g (2.57 mol) of furan was added, followed by 60 g (1.36 mol) of acetaldehyde. The resulting mixture was stirred at room temperature for 20 h, then poured into 500 mL of water and extracted with 3×250 mL of ether. The organic extracts were combined, washed with aqueous potassium bicarbonate, dried over sodium sulfate and volatiles were evaporated in vacuum. The residue was distilled in vacuum to give 60.5 g (29%) of 1,1-Di(furan-2-yl)ethane (b.p. 88-92° C./17 mm Hg) and 57.2 g (26%) of 2,5-bis[1-(2-furyl)ethyl]furan (b.p. 144-152° C./3 mm Hg).

¹H NMR (CDCl₃, 400 MHz): δ7.32 (m, 2H), 6.29 (dd, J=3.1 Hz, J=1.9 Hz, 2H), 6.04 (d, J=3.1 Hz, 2H), 4.21 (q, J=7.2 Hz, 1H), 1.59 (d, J=7.2 Hz, 3H).

¹³C{¹H} NMR (CDCl₃, 100 MHz): δ 156.5, 141.3, 110.1, 104.9, 33.0, 17.9.

CD3: 2,2-Di(furan-2-yl)propane (DFP)

2,2-Di(furan-2-yl)propane (CAS 17920-88-6), alternatively named 2,2-Bis(2-furyl)propane or 2,2′-(propane-2,2-diyl)difuran, was acquired from TCI EUROPE N.V.

CD4: Tri(furan-2-yl)methane (TFM)

To an ice-cooled mixture of 8.6 mL (103.8 mmol) of furfural and 200 mL of furan, 5 mL of trifluoroacetic acid was added dropwise and the resulting mixture was stirred at room temperature for 24 h. The reaction mixture was poured into solution of potassium bicarbonate in water, extracted with 250 mL of ether and the extract was dried over Na₂SO₄. All volatiles were removed in vacuum, and the residue was distilled in vacuum to give 3.2 g (14%) of Tri(furan-2-yl)methane (CAS 77616-90-1), alternatively named 2,2′,2″-Methanetriyltrifuran (b.p. 115° C./10 mm Hg).

¹H NMR (CDCl₃, 400 MHz): δ 7.40 (br.d, 3H), 6.36 (dd, J=3.1 Hz, J=1.9 Hz, 3H), 6.16 (d, J=3.1 Hz, 3H), 5.59 (s, 1H).

¹³C{¹H} NMR (CDCl₃, 100 MHz): δ 151.9, 142.0, 110.4, 107.3, 38.9.

CD5: 2,5-Bis[2-(tetrahydrofuran-2-yl)propan-2-yl]tetrahydrofuran (BTHFPT)

2,5-Bis[2-(tetrahydrofuran-2-yl)propan-2-yl]tetrahydrofuran (CAS 89686-70-4), alternatively named 2,5-bis[2-(oxolan-2-yl)propan-2-yl]oxolane was acquired from Fluorochem Ltd.

CD6: 2,5-Bis[1-(furan-2-yl)ethan-1-yl]furan (BFEF)

2,5-Bis[1-(furan-2-yl)ethan-1-yl]furan (CAS 61093-50-3) was prepared using slightly modified described method [J. Heterocyclic. Chem., 1991, 28, 991].

To an ice-cooled mixture of 85 mL of ethanol and 50 mL of 12 M HCl 175 g (2.57 mol) of furan was added, followed by 60 g (1.36 mol) of acetaldehyde. The resulting mixture was stirred at room temperature for 20 h, poured into 500 mL of water and extracted with 3×250 mL of ether. The organic extracts were combined, washed with aqueous potassium bicarbonate, dried over sodium sulfate and volatiles were evaporated in vacuum. The residue was distilled in vacuum to give 60.5 g (29%) of 2,2′-Ethane-1,1-diyldifuran (b.p. 88-92° C./17 mm Hg) and 57.2 g (26%) of 2,5-Bis[1-(furan-2-yl)ethan-1-yl]furan (b.p. 144-152° C./3 mm Hg).

¹H NMR (CDCl₃, 400 MHz): δ7.31 (m, 2H), 6.27 (dd, J=3.1 Hz, J=1.9 Hz, 2H), 6.00 (d, J=3.1 Hz, 2H), 5.93 (s, 2H), 4.16 (q, J=7.2 Hz, 2H), 1.56 (d, J=7.2 Hz, 6H).

¹³C{¹H} NMR (CDCl₃, 100 MHz): δ 156.7, 155.2, 141.1, 110.0, 105.4, 104.9, 33.1, 18.01, 17.96.

CD7: 2,2,7,7,12,12,17,17-Octamethyl-21,22,23,24-tetraoxaperhydroquaterene (OMTOPQ)

2,2,7,7,12,12,17,17-Octamethyl-21,22,23,24-tetraoxaquaterene

To a solution of 95.2 g (0.4 mol) of CoCl₂(H₂O)₆ in 200 mL of anhydrous ethanol, 93.2 g (1.6 mol) of acetone, 32 mL of 12 M HCl and, finally, 54.4 g (0.8 mol) of furan were successively added. After ca. 20 min, the reaction mixture became hot (60-70° C.) and turned deep-red. The reaction flask was immersed in a water bath and maintained there at 60° C. for 3 h. The reaction mixture was then stirred overnight at room temperature and poured into 500 mL of water. The resulting suspension was extracted with 3×150 mL of toluene. The combined extract's volatiles were evaporated in vacuum and the residue was triturated with 200 mL of anhydrous ethanol to give 11.1 g (13%, purity>95%) of desired product as a white powder. Re-crystallization of the crude product from hot toluene yielded analytically pure 2,2,7,7,12,12,17,17-Octamethyl-21,22,23,24-tetraoxaquaterene as a white solid.

¹H NMR (CDCl₃, 400 MHz): δ 5.88 (s, 1H), 1.47 (s, 3H).

2,2,7,7,12,12,17,17-Octamethyl-21,22,23,24-tetraoxaperhydroquaterene

A mixture of 2,2,7,7,12,12,17,17-Octamethyl-21,22,23,24-tetraoxaquaterene (5.0 g, 11.6 mmol), 5% Pd/C (710 g) and ethanol (170 mL) was placed in a 1000 mL autoclave which was then pressurized with hydrogen (100 bar). This mixture was stirred for 15 h at 125° C. After cooling to room temperature, the formed mixture was filtered through a pad of Celite 503 which was additionally washed with 100 mL of ethanol. The filtrate volatiles were evaporated in vacuum to dryness to give the first portion of the desired product (2.25 g) which was a mixture of 11 diastereomers (GC-MS). The filter cake was washed with 400 mL of dichloromethane, the filtrate volatiles were evaporated to dryness in vacuum to yield the second portion of the product (2.90 g) which was a mixture of two major diastereomers with a small amount of two minor diastereomers (GC-MS). The two portions of the product were combined. The total yield was 5.15 g (99%)) of 2,2,7,7,12,12,17,17-Octamethyl-21,22,23,24-tetraoxaperhydroquaterene (CAS 50451-63-3), alternatively named Octamethylperhydrocyclotetrafurfurylene, as a white solid.

¹H NMR of the combined portions (CDCl₃, 400 MHz): δ 4.20-3.20 (m, 8H), 2.55-1.28 (m, 16H), 1.26-0.60 (m, 24H).

CD8: 9,9-Di(methoxymethyl)fluorene (DMMF)

9,9-Di(methoxymethyl)fluorene (CAS 182121-12-6), alternatively named 9,9-Bis(methoxymethyl)-9H-fluorene, was acquired from Hangzhou Sage Chemical Co.

Inventive Internal Donors

Inventive donors ID1 to ID4 were prepared according to the following procedures:

ID1: Di(tetrahydrofuran-2-yl)methane (DTHFM)

2,2′-Methylenedifuran (19.2 g, 130 mmol; see preparation of CD1) and 5% Pd/C (0.95 g) were placed into a 450 mL autoclave which was purged with argon, pressurized with hydrogen (70 bar) and the mixture was stirred at 100° C. for 1 h. After cooling to room temperature and depressurization, the mixture was diluted with dichloromethane and filtered through a pad of Celite 503. The filtrate volatiles were evaporated in vacuum. Further on, acetic acid (20 mL) and water (80 mL) were added to the residue and the formed mixture was refluxed for 2 h under argon atmosphere. On cooling to room temperature, it was basified with a small excess of NaOH and thus obtained mixture was extracted with hexane. The extract was dried over Na₂SO₄, and the solvent was evaporated in vacuum. The residue was added drop-wise under stirring to 2.4 g of NaH under argon atmosphere. When formation of hydrogen ceased, the product was distilled off in vacuum (b.p. 54-70° C./1 mbar). Yield: 11.4 g (56%) of a colorless liquid. According to ¹H NMR the product was a ˜1: 1 mixture of diastereomers A and B of Di(tetrahydrofuran-2-yl)methane (CAS 1793-97-1), alternatively named 2,2′-Methylidenebis(tetrahydrofuran), of which A is a racemic mixture of (L) and (D) isomers and B is a meso-isomer.

¹H NMR (CDCl₃, 400 MHz): δ 3.95-3.79 (m, 4H in A and 4H in B), 3.72-3.65 (m, 2H in A and 2H in B), 2.05-1.93 (m, 2H in A and 2H in B), 1.92-1.76 (m, 4H in A and 5H in B), 1.69 (t, J=6.4 Hz, 2H in A), 1.59 (dt, J=13.6 Hz, J=5.8 Hz, 1H in B), 1.52-1.39 (m, 2H in A and 2H in B).

¹³C{¹H} NMR (CDCl₃, 100 MHz): δ 77.1, 76.9, 67.7, 67.5, 41.7, 41.1, 31.9, 31.6, 25.6, 25,5.

ID2: 1,1-Di(tetrahydrofuran-2-yl)ethane (DTHFE)

A mixture of 2,2′-(Ethane-1,1-diyl)difuran (20 g, 123 mmol; see CD2) and 5% Pd/C (1.00 g) was placed into a 450 mL autoclave which was then purged with argon and pressurized with hydrogen (70 bar). This mixture was stirred at 120° C. for 1 h. After cooling to room temperature and depressurization, the mixture was diluted with dichloromethane and filtered through a pad of Celite 503. The filtrate volatiles were evaporated in vacuum. Further on, acetic acid (20 mL) and water (80 mL) were added to the residue and the mixture was refluxed for 5 h under argon atmosphere. On cooling to room temperature, it was basified with a small excess of NaOH and then extracted with hexane. The extract was dried over Na₂SO₄ and the solvent was evaporated in vacuum. The residue was added drop-wise under stirring to 3 g of NaH under argon atmosphere. When formation of hydrogen ceased, the product was distilled off in vacuum (b.p. 75-90° C./4 mbar). Yield: 8.4 g (40%) of 1,1-Di(tetrahydrofuran-2-yl)ethane (CAS 84548-20-9), alternatively named 2,2′-Ethylidenebis(tetrahydrofuran), as a colorless liquid. According to ¹H NMR, the product was a ˜2.2: 1.1: 1 mixture of diastereomers A, B and C.

¹H NMR (CDCl₃, 400 MHz): δ3.96-3.90 (m, 2H in B), 3.86-3.76 (m, 6H in A, 4H in B, 6H in C), 1.98-1.44 (m, 9H in A, B and C), 0.97 (d, J=6.9 Hz, 3H in B), 0.87 (d, J=6.8 Hz, 3H in A), 0.80 (d, J=6.9 Hz, 3H in C).

¹³C{¹H} NMR (CDCl₃, 100 MHz): δ 81.4, 81.1, 81.0, 80.1, 68.0, 67.9, 67.8, 67.7, 42.4, 42.0, 41.3, 29.4, 29.3 (two resonances), 27.9, 26.1, 25.9, 25.7 (two resonances), 10.6, 10.3, 10.2.

ID3 and ID4: Meso-tri(tetrahydrofuran-2-yl)methane (TTHFM-A) and Rac-tri(tetrahydrofuran-2-yl)methane (TTHFM-B), Respectively

Tri(furan-2-yl)methanol

To a solution of furan (87.3 g, 1.28 mol) in THF (1000 mL) n-BuLi (500 mL, 1.25 mol, 2.5 M in hexanes) was added drop-wise at −10° C. The reaction mixture was warmed to 10° C. and stirred for 4 h at this temperature. Further on, the 2-furyllithium suspension formed was cooled to −80° C. and dimethyl carbonate (28.8 g, 320 mmol) was added. The mixture was stirred at room temperature overnight, poured into 1 L of water and extracted with 3×300 mL of diethyl ether. The combined extract was washed with 200 mL of water, dried over Na₂SO₄, passed through a pad of silica gel 60 (40-63 μm) and the volatiles were evaporated to dryness in vacuum. This procedure afforded 62.0 g of Tri(furan-2-yl)methanol of 90% purity (76% yield) as a dark brown oil which was used in the next stage without further purification.

¹H NMR (CDCl₃, 400 MHz): δ 7.43 (d, 3H, J=1.8 Hz), 6.38-6.36 (dd, 3H, J=3.2 Hz, J=1.7 Hz), 6.23 (d, 3H, J=3.2 Hz), 3.38 (s, 1H).

2,2′-(Furan-2(5H)-ylidenemethylene)difuran

To a solution of aluminum trichloride (23.2 g, 174 mmol) in anhydrous diethyl ether (1000 mL) lithium aluminum hydride (16.0 g, 416 mmol) was added portion-wise at 0° C. To the obtained solution Tri(furan-2-yl)methanol (40.0 g, 174 mmol) was added drop-wise. The mixture was stirred at 0° C. for 2 h and quenched carefully with 100 mL of water. The obtained suspension was filtered through a pad of Celite 503, the filtrate was dried over Na₂SO₄ and the volatiles evaporated to dryness in vacuum. Fractional distillation of the residue afforded 26.1 g (70%) of 2,2′-(Furan-2(5H)-ylidenemethylene)difuran as a light-brown oil (b.p. 145° C./5 mbar), containing −5 mol % of 2,2′,2″-Methanetriyltrifuran according to ¹H NMR.

¹H NMR (CDCl₃, 400 MHz): 7.43 (m, 1H), 7.38 (m, 1H), 6.70 (dt, 1H, J=6.1 Hz, J=2.3 Hz), 6.63 (d, 1H, J=3.3 Hz), 6.49 (dt, 1H, J=6.1 Hz, J=2.3 Hz), 6.44 (m, 2H), 6.36 (d, 1H, J=3.1 Hz), 5.20 (m, 2H).

Meso-tri(tetrahydrofuran-2-yl)methane (TTHFM-A) and Rac-tri(tetrahydrofuran-2-yl)methane (TTHFM-B)

A mixture of 2,2′-(Furan-2(5H)-ylidenemethylene)difuran (3.6 g, 16.8 mmol), 5% Pd/C (180 mg) and 4 mL ^(i)PrOH was placed into a 100 mL autoclave which was purged with argon, pressurized with hydrogen (70 bar) and the mixture was stirred at 100° C. for 75 min. After cooling to room temperature and depressurization, the formed mixture was diluted with dichloromethane and filtered through a pad of Celite 503. The filtrate volatiles were evaporated in vacuum and the residue was purified by column chromatography on silica gel 60 (40-63 μm, eluent: hexane/ethyl acetate, 3: 1, vol.). The procedure afforded Tri(tetrahydrofuran-2-yl)methane in form of separated stereoisomers: 0.77 g of meso-diastereomer TTHFM-A and 0.28 g of rac-diastereomer TTHFM-B. The total yield of the two diastereomers was 1.05 g (28%). Beside that, 0.78 g (22%) of 3-[Di(tetrahydrofuran-2-yl)methyl]furan were isolated.

Diastereomer TTHFM-A. ¹H NMR (CDCl₃, 400 MHz): δ 4.06-3.96 (m, 2H), 3.92-3.86 (m, 1H), 3.86-3.77 (m, 3H), 3.70-3.63 (m, 3H), 2.10-2.05 (m, 1H), 2.01-1.66 (m, 12H).

¹³C{¹H} NMR (CDCl₃, 100 MHz): δ 78.1, 78.0, 77.9, 67.6, 67.4 (two resonances), 49.2, 30.4, 29.9, 29.0, 26.0, 25.8 (two resonances).

Diastereomer TTHFM-B. ¹H NMR (CDCl₃, 400 MHz): δ 3.98-3.94 (m, 3H), 3.86-3.79 (m, 3H), 3.69-3.62 (m, 3H), 2.00-1.62 (13H).

¹³C{¹H} NMR (CDCl₃, 100 MHz): δ 78.6, 62.7, 50.5, 30.6, 25.8.

INVENTIVE AND COMPARATIVE CATALYST COMPONENTS

Inventive catalysts components (IC1- IC4) and comparative catalysts components (CC1-CC8) were prepared according to the procedure of the Reference Example 2 of WO2016/124676 A1, but using inventive donors (ID1- ID4) and comparative donors (CD1-CD8). In CC8-a and CC8-b, the same internal donor CD8 was used. Summary of donors used in catalyst component examples is disclosed in Table 1.

Comparative catalyst component CC9 is a catalyst commercially available from Grace under the trade name Lynx 200.

Raw Materials

The 10 wt % TEA (triethylaluminium) stock solutions in heptane were prepared by dilution of 100 wt % TEA-S from Chemtura.

MgCl₂*3EtOH carriers were received from Grace.

TiCl₄ was supplied by Aldrich (Metallic impurities<1000 ppm, Metals analysis>99.9%).

General Procedure for Catalyst Component Preparation

In an inert atmosphere glovebox a dry 100 mL, 4-neck round-bottom flask, equipped with two rubber septa, a thermometer and a mechanical stirrer, was charged with 3.1 mmol of a desired INTERNAL DONOR (INTERNAL DONOR and INTERNAL DONOR/Mg loading ratio are indicated in Tables 1 and 2) dissolved in 40 mL of heptane and with 7.01 g (30 mmol of Mg) of granular 17 μm (D₀₅) MgCl₂*2.93EtOH carrier. The flask was removed from the glovebox, a nitrogen inlet and an outlet were connected. The flask was placed in a cooling bath and tempered at 0° C. for approximately 10 min at 250 rpm. Triethylaluminium 10 wt % solution in heptane (107.55 g, 94.2 mmol Al; Al/EtOH=1.07 mol/mol) was added drop-wise to the stirred suspension within 1 h, keeping the reaction mixture temperature below 0° C. The obtained suspension was heated to 80° C. within 20 min and kept at this temperature for further 30 min at 250 rpm. The suspension was left to settle for 5 min at 80° C. and the supernatant was removed using a cannula. The obtained pre-treated support material was washed twice with 70 mL of toluene at room temperature (adding toluene, stirring at 250 rpm for 15-120 min, settling for 5 min and siphoning the liquid phase off).

At room temperature, 70 mL of toluene was added to the pre-treated support material. To this suspension stirred at 250 rpm, neat TiCl₄ (3.31 mL, 30 mmol; Ti/Mg=1.0 mol/mol) was added drop-wise and the reaction mixture temperature was maintained between 25-35° C. The obtained suspension was heated to 90° C. within 20 min and stirred at this temperature for further 60 min at 250 rpm. The suspension was left to settle for 5 min at 90° C. and the supernatant was removed suing a cannula. The obtained catalyst was washed twice with 70 mL of toluene at 90° C. and once with 70 mL of heptane at room temperature (each wash involving adding toluene or heptane, stirring at 250 rpm for 15 min, settling for 5 min and siphoning the liquid phase off). The catalyst was dried in vacuo at 70° C. for 30 min.

TABLE 1 Summary of donors used in catalyst components CC1-CC8 and IC1-IC4 Catalyst Internal Donor Examples component Internal Donor short name Comparative CC1 CD1 DFM Comparative CC2 CD2 DFE Comparative CC3 CD3 DFP Comparative CC4 CD4 TFM Comparative CC5 CD5 BTHFPT Comparative CC6 CD6 BFEF Comparative CC7 CD7 OMTOPQ Comparative CC8-a CD8 DMMF Comparative CC8-b CD8 DMMF Inventive IC1 ID1 DTHFM Inventive IC2 ID2 DTHFE Inventive IC3 ID3 TTHFM-A Inventive IC4 ID4 TTHFM-B

Comparative Examples

CC1 Preparation

CC1 was prepared using the above General Procedure, with a difference that 0.45 g (3.1 mmol) of CD1 (DFM) were used as internal donor (ID/Mg=0.102).

3.8 g (94.8% yield, Mg-basis) of CC1 were isolated.

CC2 Preparation

CC2 was prepared using the above General Procedure, with a difference that 0.50 g (3.1 mmol) of CD2 (DFE) were used as internal donor (ID/Mg=0.102).

3.6 g (82.4% yield, Mg-basis) of CC1 were isolated.

CC3 Preparation

CC3 was prepared using the above General Procedure, with a difference that 0.54 g (3.1 mmol) of CD3 (DFP) were used as internal donor (ID/Mg=0.102).

3.0 g (68.3% yield, Mg-basis) of CC3 were isolated.

CC4 Preparation

CC4 was prepared using the above General Procedure, with a difference that 0.66 g (3.1 mmol) of CD4 (TFM) were used as internal donor (ID/Mg=0.102).

3.8 g (78.2% yield, Mg-basis) of CC4 were isolated.

CC5 Preparation

CC5 was prepared using the above General Procedure, with a difference that 0.34 g (1.2 mmol) of CD5 (BTHFPT) were used as internal donor (ID/Mg=0.039).

3.3 g (85.5% yield, Mg-basis) of CC5 were isolated.

CC6 Preparation CC6 was prepared using the above General Procedure, with a difference that 0.78 g (3.1 mmol) of CD6 (BFEF) were used as internal donor (ID/Mg=0.102).

4.0 g (89.9% yield, Mg-basis) of CC6 were isolated.

CC7 Preparation

CC7 was prepared using the above General Procedure, with a difference that 1.37 g (3.1 mmol) of CD7 (OMTOPQ) were used as internal donor (ID/Mg=0.102).

5.9 g (95.5% yield, Mg-basis) of CC7 were isolated.

CC8-a Preparation

CC8-a was prepared using the above General Procedure, with a difference that 0.778 g (3.1 mmol) of CD8 (DMMF) were used as internal donor (ID/Mg=0.102).

2.3 g (57.4% yield, Mg-basis) of CC8-a were isolated.

CC8-b Preparation

CC8-b was prepared using the above General Procedure, with a difference that 1.038 g (4.1 mmol) of CD8 (DMMF) were used as internal donor (ID/Mg=0.136).

2.8 g (64.5% yield, Mg-basis) of CC8-b were isolated.

Inventive Examples

IC1 Preparation

IC1 was prepared using the above General Procedure, with a difference that 0.48 g (3.1 mmol) of ID1 (DTHFM) were used as internal donor (ID/Mg=0.102).

3.9 g (84.0% yield, Mg-basis) of 101 were isolated.

IC2 Preparation

IC2 was prepared using the above General Procedure, with a difference that 0.52 g (3.1 mmol) of ID2 (DTHFE) were used as internal donor (ID/Mg=0.102).

4.7 g (93.4% yield, Mg-basis) of 102 were isolated.

IC3 Preparation

IC3 was prepared using the above General Procedure, with a difference that 0.69 g (3.1 mmol) of ID3 (TTHFM-A) were used as internal donor (ID/Mg=0.102).

5.2 g (96.9% yield, Mg-basis) of 103 were isolated.

IC4 Preparation

IC4 was prepared using the above General Procedure, with a difference that 0.46 g (2.0 mmol) of ID4 (TTHFM-B) were used as internal donor (ID/Mg=0.068).

4.7 g (96.7% yield, Mg-basis) of 104 were isolated.

TABLE 2 Summary of properties of catalyst components CC1-CC8 and IC1-IC4 ID/Mg loading Mg/Ti Mg/Al Catalyst Internal ratio, Ti, Mg, Al, Cl, Volatiles, Ti(IV) ratio, ratio, component donor (ID) mol/mol wt % wt % wt % wt % wt % proportion, % mol/mol mol/mol CC1 DFM 0.102 5.63 18.2 0.98 60.5 4.1 38.5 6.37 20.62 CC2 DFE 0.102 5.26 16.7 0.93 62.0 1.8 27.8 6.25 19.93 CC3 DFP 0.102 6.33 16.6 1.21 60.8 5.5 39.5 5.16 15.23 CC4 TFM 0.102 4.06 15.0 0.80 57.2 7.7 38.6 7.28 20.82 CC5 BTHFPT 0.039 5.57 18.9 0.72 63.0 4.0 26.1 6.68 29.14 CC6 BFEF 0.102 5.09 16.4 0.91 60.1 3.5 25.4 6.35 20.01 CC7 OMTOPQ 0.102 7.38 11.8 1.13 51.2 7.4 7.7 3.15 11.59 CC8-a DMMF 0.102 3.54 18.2 0.23 56.3 4.7 40.0 10.13 87.85 CC8-b DMMF 0.136 4.00 16.8 0.37 55.2 5.4 26.2 8.27 50.41 IC1 DTHFM 0.102 5.34 15.7 0.64 59.4 5.4 6.2 5.79 27.23 IC2 DTHFE 0.102 4.65 14.5 0.75 52.0 16.9 9.3 6.14 21.46 IC3 TTHFM-A 0.102 7.75 13.7 1.48 58.2 6.1 17.4 3.48 10.28 IC4 TTHFM-B 0.068 6.37 15.0 1.09 55.5 10.3 21.7 4.64 15.28

Bench-Scale Copolymerization with 1-Butene

The inventive catalyst components (IC1-IC4) and comparative catalyst components (CC1-CC7, CC8-a-CC8-b and CC9) were tested in copolymerization with 1-butene (IE1-IE4, CE1-CE7, CE8-a, CE8-b and CE9-a-CE9-c). Triethylaluminum (TEA) was used as a cocatalyst with an Al/Ti molar ratio of 15. The polymerization reaction was carried out in a 3 L bench-scale reactor in accordance with the following procedure:

An empty 3 L bench-scale reactor was charged with 70 mL of 1-butene at 20° C. and stirred at 200 rpm. Then 1250 mL of propane was added to the reactor as a polymerization medium, followed by the addition of hydrogen gas (0.40 bar). The reactor was heated to 85° C. and ethylene (3.7 bar) was added batch-wise. The reactor pressure was kept at 0.2 bar of overpressure and stirring speed was increased to 550 rpm. The catalyst component and the cocatalyst were added together (a few seconds of pre-contact between catalyst component and TEA) to the reactor with additional 100 mL of propane. The total reactor pressure was maintained at 37.8 bar by continuous ethylene feed. The polymerization was stopped after 60 min by venting off the monomers and H₂. The obtained polymer was left to dry in a fume hood overnight before weighing.

Additionally, the comparative catalyst component CC9 was tested in copolymerization also with 55 mL of 1-butene and 0.40 bar of hydrogen gas (CE9-b) and with 40 mL of 1-butene and 0.75 bar of hydrogen gas (CE9-c).

Polymerization Results

The results of the polymerization reactions are shown in Table 3. The activity of the catalysts was calculated based on catalyst component loading amount and the amount of polymer produced in one hour.

TABLE 3 Summary of polymerization results for comparative examples CE1- CE7, CE8-a-CE8-b, CE9-a-CE9-c and inventive examples IE1-IE4. Polymerization Catalyst Activity, 1-Butene MFR₂₁, M_(W), T_(M), Example component kg/(g*h) content, wt % g/10 min g/mol PDI ° C. CE1 CC1 26.6 7.1 16.9 145000 4.99 123.23 CE2 CC2 21.7 7.5 18.5 146000 5.01 122.53 CE3 CC3 8.6 heavy fouling n.a. n.a. n.a. n.a. CE4 CC4 19.0 6.0 8.8 164500 4.67 122.96 CE5 CC5 23.7 6.3 11.0 181500 4.81 122.92 CE6 CC6 24.4 6.3 13.4 155000 4.82 122.56 CE7 CC7 2.7 3.4 4.3 189000 4.96 124.05 CE8-a CC8-a 19.2 4.4 3.7 211500 4.61 122.85 CE8-b CC8-b 17.3 4.8 3.9 215500 4.52 123.16 CE9-a CC9 55 6.2 5.3 200000 4.80 122.4 CE9-b CC9 54 4.8 3.0 220000 4.71 123.4 CE9-c CC9 58 3.9 8.3 160000 4.64 124.9 IE1 IC1 18.7 3.5 1.7 251500 4.05 122.43 IE2 IC2 20.7 4.0 2.2 247500 4.13 122.47 IE3 IC3 9.0 3.4 1.5 267500 3.94 122.75 IE4 IC4 19.0 3.6 1.6 256000 4.00 123.07

As can be seen from the results of the Table 3 and as indicated in FIGS. 1 to 3 , all inventive examples IE1-IE4 exhibit narrower MWD and higher M_(W) than comparative examples CE1-CE9(a-c).

Further, all inventive examples IE1-IE4 demonstrate a lower melting temperature at a given comonomer content than comparative examples CE1-CE9(a-c).

All inventive examples IE1-IE4 possess an activity level similar to comparative examples CE1-CE8 but with a much higher M_(W) capability.

Moreover, in all inventive examples IE1-IE4 the desired balance of properties is achieved with ID/Mg loading ratios similar or lower than those that have to be employed for the comparative internal donor CD8.

To summarize the findings, all inventive examples IE1-IE4 demonstrate the highest (among the tested group of catalyst components/internal donors) M_(W) combined with a very narrow MWD and with the lowest melting temperatures at a given comonomer content. Thus, the inventive internal donors allow for tailoring of the properties of the produced polymers while maintaining the catalyst productivity at an acceptably high level. 

1.-2. (canceled)
 3. A Ziegler-Natta catalyst component for olefin polymerization, comprising: (i) an internal donor selected from compounds of formula (I)

wherein R₁ is selected from a group consisting of H, a linear or branched C₁₋₇-alkyl, CH₂OR₂ and oxygen-containing heterocyclic ring; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.
 4. The Ziegler-Natta catalyst component according to claim 3, wherein the compound of formula (I) is selected from compounds of formula (I-a) and (I-b)

wherein in (I-a) R_(1a) is selected from a group consisting of H, C₁₋₃-alkyl and CH₂OR₂; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group, and wherein in (I-b) R_(1b) is selected from a group consisting oxygen-containing heterocyclic ring.
 5. The Ziegler-Natta catalyst component according to claim 3, further comprising: (ii) a transition metal compound of Group 4 to 6 of the Periodic Table (IUPAC, Nomenclature of Inorganic Chemistry, 2005); (iii) a metal compound of Group 1 to 3 of the Periodic Table (IUPAC, 2005); and (iv) optionally, a compound of group 13 of the Periodic Table (IUPAC, 2005).
 6. The Ziegler-Natta catalyst component according to claim 3, wherein the Ziegler-Natta catalyst component comprises: (ii) a Group 4 to 6 metal content (determined by ICP Analysis) in the range of 1.0 wt % to 15.0 wt % of the total weight of the Ziegler-Natta catalyst component; (iii) a Group 1 to 3 content (determined by ICP Analysis) in the range of 5.0 wt % to 30.0 wt % of the total weight of the Ziegler-Natta catalyst component; (iv) a Group 13 element content (determined by ICP Analysis) in the range of 0.0 wt % to 3.0 wt % of the total weight of the Ziegler-Natta catalyst component.
 7. A method for producing a Ziegler-Natta catalyst component, comprising adding an internal donor selected from compounds of formula (I)

wherein R₁ is selected from a group consisting of H, a linear or branched C₁₋₇-alkyl, CH₂OR₂ and oxygen-containing heterocyclic ring; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group, to a process of preparing the Ziegler-Natta catalyst component.
 8. A method for producing a Ziegler-Natta catalyst component according to claim 3, wherein the method comprises: (M-a) providing a solid support; (M-b) pre-treating the solid support of step (M-a) with a compound of Group ₁₃ element; (M-c) treating the pre-treated solid support of step (M-b) with a transition metal compound of Group 4 to 6; (M-d) recovering the Ziegler-Natta catalyst component; wherein the solid support is contacted with an internal organic compound of formula (I) or mixtures therefrom before treating the solid support in step (M-c).
 9. The method according to claim 7, wherein the Ziegler-Natta catalyst component is the Ziegler-Natta catalyst component according to claim
 3. 10. A Ziegler-Natta catalyst for olefin polymerization comprising a catalyst component comprising an internal donor selected from compounds of formula (I)

wherein R₁ is selected from a group consisting of H, C₁₋₃-alkyl, CH₂OR₂ and oxygen-containing heterocyclic ring; and R₂ is selected from a group consisting of a linear, branched or cyclic C₁₋₈-alkyl group; or the internal donor is selected from compounds of formula (I-a) or (I-b)

wherein in (I-a) R_(1a) is selected from a group consisting of H, C₁₋₃-alkyl and CH₂OR₂; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group, and wherein in (I-b) R_(1b) is selected from a group consisting oxygen-containing heterocyclic ring.
 11. The Ziegler-Natta catalyst according to claim 10, comprising (A) the Ziegler-Natta catalyst component as defined in claim 3, or produced according to the method according to claim 7; (B) a cocatalyst selected from element compounds of Group 13 of the Periodic Table (IUPAC, 2005); and (C) optionally, an external donor.
 12. A method of olefin polymerization comprising: introducing into a polymerization reactor a Ziegler-Natta catalyst component according to claim 3 comprising an internal donor of formula (I)

wherein R₁ is selected from a group consisting of H, a linear or branched C₁₋₇-alkyl, CH₂OR₂ and oxygen-containing heterocyclic ring; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group.
 13. The method according to claim 12, wherein the internal donor of formula (I) is selected from compounds of formula (I-a) or (I-b)

wherein in (I-a) R_(1a) is selected from a group consisting of H, C₁₋₃-alkyl and CH₂OR₂; and R₂ is selected from a group consisting of a linear or branched or cyclic C₁₋₈-alkyl group, and wherein in (I-b) Rib is selected from a group consisting of oxygen-containing heterocyclic ring.
 14. The method according to claim 12, wherein the internal donor is comprised in a Ziegler-Natta catalyst component further comprising (ii) a transition metal compound of Group 4 to 6 of the Periodic Table (IUPAC, Nomenclature of Inorganic Chemistry, 2005); (iii) a metal compound of Group 1 to 3 of the Periodic Table (IUPAC, 2005); and (iv) optionally, a compound of group 13 of the Periodic Table (IUPAC, 2005).
 15. The method according to claim 12, wherein the Ziegler-Natta catalyst component comprises (ii) a Group 4 to 6 metal content (determined by ICP Analysis) in the range of 1.0 wt % to 15.0 wt % of the total weight of the Ziegler-Natta catalyst component; (iii) a Group 1 to 3 content (determined by ICP Analysis) in the range of 5.0 wt % to 30.0 wt % of the total weight of the Ziegler-Natta catalyst component; (iv) an Al content (determined by ICP Analysis) in the range of 0.0 wt % to 3.0 wt % of the total weight of the Ziegler-Natta catalyst component.
 16. A process for producing ethylene homo- or copolymers, comprising: (P-a) introducing the Ziegler-Natta catalyst component according to claim 3, or produced according to the method according to claim 7 into a polymerization reactor; (P-b) introducing a cocatalyst capable of activating the said Ziegler-Natta catalyst component into the polymerization reactor; (P-c) introducing ethylene, optionally C₃-C₂₀ α-olefin comonomers, and optionally hydrogen into the polymerization reactor; and (P-d) maintaining said polymerization reactor in such conditions as to produce an ethylene homo- or copolymer.
 17. The process according to claim 16, wherein olefin polymerization is accomplished in a multi-stage polymerization process comprising at least one gas phase reactor for producing olefin polymers.
 18. The process according to claim 16, wherein olefin polymerization is accomplished in a multi-stage polymerization process comprising at least one slurry reactor and one gas phase reactor. 